Putter

ABSTRACT

A putter club having a relatively hard face insert supported by at least one dampening layer is disclosed. The putter club also has an internal weight positioned in line with the center of gravity of the club. The putter club has a body and a sole plate wherein the density of the body is substantially higher than the density of the sole plate. A vibration dampening system for a golf club is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of co-pending U.S. application Ser.No. 10/704,774, filed Nov. 10, 2003.

FIELD OF THE INVENTION

This invention generally relates to golf clubs, and more particularlyrelates to putter golf clubs.

BACKGROUND OF THE INVENTION

Golf clubs, particularly the clubs used on and around the greens, havelong been developed to improve the touch and feel for the golfers.Conventional approaches to improve touch and feel include modifying thegrip, the shaft or the strike face of the clubs. In one example, U.S.Pat. No. 6,231,458 B1 discloses an insert on the strike face thataffects the rebound of the golf ball at impact with the strike face. The'458 patent further discloses a dampening layer located behind theinsert that dampens the vibrations caused by the impact and improves thetouch and feel feedback to the golfers. The amount of feedback can becontrolled by the amount of contact between the face insert and thedampening layer. To improve touch and feel, the insert is made from arelatively soft tellurium copper alloy.

In another example, U.S. Pat. No. 6,238,303 B1 discloses a putter clubhaving a user-replaceable face insert. The insert is selected to havedifferent weight, texture and hardness. The user can choose a particularinsert for the club to match the club's putting characteristics to thegreen's conditions. The insert can be fabricated from titanium,graphite, polytetrafluoroethylene (PTFE), copper, brass, plastics,aluminum, carbon steel, stainless steel among others.

However, the prior art does not contemplate a putter that has a strikingface with properties that are uniquely different from other parts of theclub.

SUMMARY OF THE INVENTION

Hence, the present invention is directed to a putter club having a faceinsert.

The present invention is also directed to a putter club having arelatively hard face insert supported by at least one dampening layer.

The present invention is directed to a system of vibration dampeners fora golf club.

The present invention is also directed to a putter club having aninternal weight positioned in line with the center of gravity of theclub.

The present invention is also directed to a putter club with a body anda sole plate wherein the density of the body is substantially higherthan the density of the sole plate.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which form a part of the specification andare to be read in conjunction therewith and in which like referencenumerals are used to indicate like parts in the various views:

FIG. 1 is a perspective exploded front view of the putter in accordancewith the present invention showing the insert and the putter body;

FIG. 2 is a perspective back view of the putter in FIG. 1;

FIG. 3 is a perspective bottom view of the putter in FIG. 1;

FIG. 4 is exploded view of the putter in FIG. 1 showing the sole plateand the bottom of the putter body; and

FIG. 5 is a front view of the putter of FIG. 1 showing the insert andthe hitting face.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Putter club head 10 in accordance with an embodiment of the presentinvention is illustrated in FIGS. 1-5. Club head 10 comprises front 12,back 14, top 16, sole 18, heel 20, toe 22 and hosel 24. Hosel 24 isattachable to one end of a shaft and a grip is attached to the shaft atthe opposite end. In a preferred embodiment, club head 10 is a mallettype putter and has face insert 26 attachable to the club head body,designated collectively as reference number 28, to form front 12. Asshown, insert 26 has a shape that is substantially the same as front 12and is dimensioned to fit inside the perimeter of face 12. A gap 40 isdefined on face 12 around insert 26, as illustrated in FIG. 5. Thethickness of insert 26 can be constant, or can vary. As shown, insert 26is relatively thick, except in the vicinity of the hosel where insert 26is thinner. The present invention, however, is not limited to the sizeand shape of the insert illustrated and described herein. Insert 26 canbe attached to body 28 by any conventional means, including welding,threaded fasteners, adhesives, etc., discussed below. The loft angle offront 12 is preferably about 0° to about 6°, and more preferably about4°.

As best shown in FIGS. 1 and 2, top 16 may have any contour, shape oraesthetic designs. Top 16 comprises front region 32 proximate front 12and a mallet-shaped extension. The mallet-shaped extension has concavingtop surface 34 surrounded by border region 36. For additionaldistinctiveness, concaving surface 34 has a plurality of score lines 38.The present invention, however, is not limited to mallet putter clubs orto any particular aesthetic designs.

Sole plate 18 is preferably made separate from body 28 and is attachedthereto by any conventional means, such as threaded fasteners, as bestshown in FIGS. 2 and 4. As illustrated, body 28 is hollow; however, itis understood that the present invention is not limited to hollow clubheads. Weight 30 is attachable to sole 18 to alter the mass of the clubhead. In one embodiment, weight 30 is added to club head 10 when thelength of the shaft is less than about 35 inches, and preferably whenthe shaft length is about 33 inches to about 34 inches. In oneembodiment, when the shaft length is about 35 inches, weight 30 is zero.When the shaft length is about 34 inches, weight 30 is about 10 grams,and when the shaft length is about 33 inches, weight 30 is about 20grams. Sole plate 18 may also include indicia on the outside surface toindicate the shaft length, as shown in FIG. 3.

In accordance to one aspect of the present invention, weight 30 ispositioned at a location directly behind the center of gravity of putter10. When putter 10 strikes a golf ball at its center of gravity, weight30 would line up on an imaginary line connecting the center of gravityof the club to the center of gravity of the ball. More preferably, thecenter of gravity of weight 30 lines up with this imaginary line. Inother words, weight 30 is positioned such that it lines up with thecenter of gravity of the club in the X, Y and Z directions. Suchdisposition of weight 30 advantageously minimizes vibration when theputter strikes a ball.

In accordance to another aspect of the present invention, preferablydisposed between insert 26 and body 28 is a first dampening layer X.Dampening layers in putter golf clubs are fully disclosed in commonlyowned U.S. Pat. No. 6,231,458 B1, which is incorporated herein byreference in its entirety. Suitable dampening materials include anymaterials, such as polymeric materials, that posses the appropriatetangent of delta to absorb vibrations generated by impacts with golfballs and to improve the touch and feel of the club. Optional screws, asillustrated in FIG. 2, may also be used to attach insert 26 to body 28.These optional screws can also be used to hold insert 26 tightly againstbody 28. Suitable dampening materials include, but are not limited to,silicone materials, such as Stock No. GE281 from General Electric, andfoamed rubbers or elastomers.

A second dampening layer Y can be provided in gap 40 between insert 26and the rest of face 12 to further dampen vibration. Preferably, thesecond dampening layer is made from silicone material. Furthermore, athird dampening layer Z can be provided between weight 30 and sole 18,and preferably third dampening layer Z is made from the same material asthe first dampening layer.

In accordance to one aspect of the present invention, insert 26 is madefrom a substance that is relatively hard, i.e., having high hardnessmeasurement. In one example, the insert is made from a grade 303stainless steel commercially available from Monstanstahl AG of Germany(hereinafter SS 303 DE), and the body is made from other commercialgrade 303 annealed stainless steel and the sole plate is made fromcommercial grade aluminum alloy 6061. The tables below summarize thechemical make-up and mechanical properties of the different parts ofclub head 10. TABLE 1 Chemical Compositions Carbon Chromium NickelNitrogen Sulfur Iron Insert 26 (SS 303 DE) 0.15% 17%-19% 8%-10% — 0.15%min. Remaining Body 28 (SS 303) 0.15% 17%-19% 8%-10% 0.15% min RemainingCopper Silicone Manganese Magnesium Chromium Aluminum Sole 18 (Aluminum0.28% 0.6% — 1.0% 0.20% Remaining alloy 6061)

TABLE 2 Mechanical Properties Tensile Yield Elongation Strength Strengthbefore Hardness Density (kpsi) (kpsi) break (Brinell) (lb/in³) Insert 26109 71 40% 183 0.289 (SS 303 DE) Body 28  75-90 30-40 35%-50% 262 0.289(SS 303) Sole 18  8 & 40 18 & 45 25% & 12%  30 & 95 0.098 (Aluminumalloy 6061)

Brinell hardness is measured by forcing a hard steel or carbide sphereof a specified diameter under a known applied force for a known durationof time. The Brinell hardness number is obtained by dividing the forceof the load used in kilogram by the actual surface area of theindentation caused by the sphere in square millimeters. The Brinellhardness number, therefore, has a unit similar to that of pressure. Foraluminum and other soft metals, the applied force used is 500 kg. Forthe harder irons and steels, the applied force used is 3000 kg. The timeperiod that the force is applied is about 10-15 seconds. Preferably,hardness tests are conducted under the ASTM E-10 standard.

The mechanical properties listed above for stainless steel 303 representtypical properties for stainless steels 303 that have been annealed, andthe mechanical properties listed for SS 303 DE are the properties forthe stainless steel 303 produced by Monstanstahl AG, which is thepreferred material for insert 26. Although insert 26 and body 28 can bemade from the same material, e.g., stainless steel 303, insert 26 issofter (lower hardness) but has higher yield strength and tensilestrength than body 28.

Two sets of numbers are given for aluminum alloy 6061. The first setcorresponds to the annealed alloy and the second set corresponds to thealloy that had been tempered. Both alloys are suitable for sole 18. Theannealed aluminum alloy 6061 is more preferred due to its softness forease of manufacturing. Additionally, aluminum alloy 6061 has a densitythat is about 3 times less than the density of stainless steel 303, andwhen used in the sole plate can move the center of gravity of the putterupward to a more desirable position.

The inventor of the present invention believes that a combination of arelatively hard hitting face provided by the hard insert with more thanone dampening layer supporting the hard insert provides the putter withbetter touch and feel.

While it is apparent that the illustrative embodiments of the inventiondisclosed herein fulfill the objectives stated above, it is appreciatedthat numerous modifications and other embodiments may be devised bythose skilled in the art. Therefore, it will be understood that theappended claims are intended to cover all such modifications andembodiments, which would come within the spirit and scope of the presentinvention.

1. A putter comprising a club head having a body comprising a frontportion and a back portion, wherein the front portion has an insertsupported by a dampening layer and the insert has a Brinell hardness ofat least about
 150. 2. The putter of claim 1, wherein the Brinellhardness of the insert is lower than a Brinell hardness of the body byless than
 100. 3. The putter of claim 1, wherein a tensile strength ofthe insert is higher than a tensile strength of the body.
 4. The putterof claim 1, wherein a yield strength of the insert is higher than ayield strength of the body.
 5. The putter of claim 1, wherein the inserthas a Brinell hardness of less than about
 200. 6. The putter of claim 2,wherein the difference in Brinell hardness is at least about
 10. 7. Theputter of claim 6, wherein the difference in Brinell hardness is atleast about
 25. 8. The putter of claim 7, wherein the difference inBrinell hardness is at least about
 50. 9. The putter of claim 1, whereinthe back portion comprises a mallet type extension.
 10. The putter ofclaim 1, further comprising a sole plate attachable to the body and madefrom a material with a density lower than a density of the body.
 11. Theputter of claim 10, wherein the sole plate is made from a non-ferrousmaterial.
 12. The putter of claim 11, wherein the sole plate is madefrom aluminum alloy.
 13. The putter of claim 10, wherein the density ofthe body is at least about twice the density of the sole plate.
 14. Theputter of claim 13, wherein the density of the body is at least aboutthree times the density of the sole plate.
 15. The putter of claim 1,further comprising a weight member positioned within the body such thata center of gravity of the putter coincides with the weight member. 16.The putter of claim 15, wherein a center of gravity of the weight memberis positioned approximate the center of gravity of the putter.
 17. Theputter of claim 1, wherein the dampening layer is located on a backsurface of the insert.
 18. The putter of claim 1, further comprising asecond dampening layer visible on the front portion and positionedaround the insert.
 19. The putter of claim 1, further comprising a thirddampening layer positioned between a weight member and a sole plateattached to the body.
 20. The putter of claim 19, wherein the thirddampening layer attaches a weight member to the sole plate.